This is a Combo widget for Gtk+. 

It's a composite widget (an HBox) and it has an entry and a list.
You can use it like an entry and to track changes you should connect
to the "changed" signal of combo->entry.
Add the items of the list to the combo->list GtkList widget.

The list can contain anything, but you should supply a function
if you want to use widgets other than GtkLabels to get a string out
of your widgets (an example is provided for a two-column list).
The value in the entry can be limited to those in the list
using gtk_combo_set_value_in_list().
In the entry you can hit enter to popup the list or use the
arrow keys to change the value to that prior or next of
the current value.

It would be useful to add completion support in the entry.

Have fun.

For comments mail lupus@lettere.unipd.it.